Crack Meters are used to monitor movement across surface cracks and joints in concrete structures or rock. This system is used as Joint Meter also.

The Crack meters of PMT consists of a vibrating wire sensing element anchored at one end and connected to a spring loaded rod at the other end. It is installed by two threaded anchors or grouting on opposite sides of the joint and the sensor is mounted across the anchors. A change in the crack across two anchors changes the tension corresponding to change in its electrical signal which is transmitted through a cable to the readout unit.

Specifications
Model: 1201V-CM-L / 3201P-CM-L
Sensor Type: Vibrating wire/Potentiometer
Sensor range: 25, 59, 100,150, 200mm
Resolution: 0.02% F.S.
Accuracy: ±0.1% F.S.
Nonlinearity: <0.5% F.S.
Temperature Range: -20 to 80° C
Cable: 4/2-wire, shielded, polyurethane jacket
CRACK METER (VW)

Crack Meter (Tri-axial/3D) is intended to monitor movement across surface cracks and joints in concrete structures or rock in three directions. This system is used as Tri-axial/3D Joint Meter also.

The ial Crack Meter (Mechanical) of PMT is designed to manually measure the displacement across cracks and/or expansion joints in three directions. It is used for surface measurement where measurement is made by anchoring the two element on either side of joint/crack and accurately measuring the distance between them over period of time with depth gage of 25/50/100 mm range and 0.01 mm resolution.

For Vibrating Wire/Potentiometeric Crackmeters this item has three sets of displacement transducer assemblies installed across the crack in three mutually perpendicular directions. Free movement of the sliding shaft in all directions ensures accuracy of measurement.

Specifications | Electrical
Model: 1201V-CM-T / 3201P-CM-LT
Sensor Type: Vibrating wire/Potentiometer
Sensor range: 25, 50, 100,150, 200mm
Resolution: 0.02% F.S. (VW), 0.01mm (Potentiometer)
Accuracy: ±0.1% F.S.
Non-linearity: <0.5% F.S.
Temperature Range: -20 to 80° C
Cable: 4-wire, shielded, polyurethane jacket
Specifications | Mechanical
Model: 1201V-CM-T / 3201P-CM-LT
Sensor Type: Mechanical
Sensor range: 25, 50, 100mm
Resolution: 0.01mm
Resolution: 0.02% F.S.
Accuracy: ±0.1% F.S.
Temperature Range: -20 to 80° C
Material: Stainless Steel
CRACK METER (TRI-AXIAL3D)

Joint Meter is commonly used for strain measurements in foundations, piles, bridges, dams, tunnel linings, etc.. This can be used either as surface mount application, embedded application or for 3-D/trai-axial/perimetric monitoring purpose.

The Joint Meter of PMT consists of a vibrating wire sensing element anchored at one end and connected to a spring loaded push rod at the other end. For triaxial/3D measurement, this item can be assembled with three sets of transducers installed across the crack in three mutually perpendicular directions. As the push rod is moved out from the transducer body the spring is elongated causing an increase in the vibrating wire tension. This tension is directly proportional to the spring extension and therefore the joint opening or closing resulting into change in its frequency signal which is transmitted through a cable to the readout unit.

Specifications
Model: 1201V-JM-E / 1201V-JM-L / 1201V-JM-T
Sensor Type: Vibrating wire
Sensor range: 25, 59, 100,150, 200mm
Resolution: 0.02% F.S.
Accuracy: ±0.1% F.S.
Nonlinearity: <0.5% F.S.
Temperature Range: -20 to 80° C
Cable: 4-wire, shielded, polyurethane jacket
JOINT METER